What type of bolt is this?

[yamaha1300rider]

I am planning to replace some of my tarnished bolts with stainless steel equivalents.

However, I withdrew the lower 2 bolts on the gear change plate (which also hold the side stand) and am confused re the type and length of the bolt:

Bolt

You can clearly see there are no threads on the tip of the bolt - is this significant? :glare:

Also, from the underside of the head to the end of the threads the length is 40mm, but to the end of the bolt is about 43-44mm. Presumably I go for a 40mm in SS? :blink:

 

[odot]

It's a bolt for retarded people who have a hard time threading bolts into their respective places.

You could probably easily get away with a regular bolt.....as long as you don't have a problem threading it. :lol:

 

[Warchild]

I am planning to replace some of my tarnished bolts with stainless steel equivalents.
However, I withdrew the lower 2 bolts on the gear change plate (which also hold the side stand) and am confused re the type and length of the bolt:

Bolt

You can clearly see there are no threads on the tip of the bolt - is this significant? :glare:

Yes, it is absolutely significant!

These "shouldered" bolts are typically weight-bearing (In this case, the weight it is bearing is the weight of your bike while propped up onm the side-stand.... so I'd classify this bolt as being damn significant! .

If you're determined to replace it, my advice is for you to replace it with an identical SS equivalent. If I could not find an equivalent bolt, then I (personally) would stay with this stock bolt.

 

[twowheelnut]

Er, lemme get in my wayback machine, Sherman...

Isn't stainless steel softer than hardened steel when it comes to sheer forces and thus should not be used for high strength work? Or do I have it backwards...

 

[Bullit]

Er, lemme get in my wayback machine, Sherman...
Isn't stainless steel softer than hardened steel when it comes to sheer forces and thus should not be used for high strength work? Or do I have it backwards...

Stainless is softer than steel, make sure to note the bolt hardness, should be stamped on the head. Stainless would be fine for low torque areas, it will stretch with higher torques and cause all kinds of crap.

 

[yamaha1300rider]

Warchild

Yes, it is absolutely significant!
These "shouldered" bolts are typically weight-bearing (In this case, the weight it is bearing is the weight of your bike while propped up onm the side-stand.... so I'd classify this bolt as being damn significant! .

If you're determined to replace it, my advice is for you to replace it with an identical SS equivalent. If I could not find an equivalent bolt, then I (personally) would stay with this stock bolt.

Agreed, but my question was "Is the tip significant and *NOT* the bolt itself.

TWN

Isn't stainless steel softer than hardened steel when it comes to sheer forces and thus should not be used for high strength work? Or do I have it backwards...

True but most of the time the bolt is in tension and shear forces only act when bike on side stand and there are 2 of them

 

[odot]

Ya know....they do make "shiny bolt covers". It's mostly us harley guys that like the chrome look. They look really shiny when you are pushing them down the road.

 

[yamaha1300rider]

odot, that's a great idea - thanks

All I've got to do now is find some

 

[yamaha1300rider]

Bullit

Stainless is softer than steel, make sure to note the bolt hardness, should be stamped on the head. Stainless would be fine for low torque areas, it will stretch with higher torques and cause all kinds of crap.

Problem is cap screws don't show the hardness on the head. Edit: My bad, they do show the strength 70 or 80 usually.

Another complication is that uk manufacturers say SS do not need to be stretched and so when used with anti-seize only use a torque of 2/3 of oem

What confuses me with all this replacement of rusty bolts by SS or Ti is the need not to do so where a siginicant stress is likely to occur. Radman has warned me off not using SS in the bottom shock bolt and WC for the side stand bolts - I appreciate this guys as I don't want to put my life at risk.

And yet a number of members on this site, including WC have replaced their front caliper bolts with Ti - surely these are subject to shear forces when braking :blink: So I assumed that, unless the bolt was marked on the head as high tension it was ok to replace with SS.

Anyway I have replaced my caliper bolts with raised hex bolts:

My New Caliper Bolt

Any further general quidelines on replacing oem bolts with SS are appreciated

 

[bikerschim]

I am planning to replace some of my tarnished bolts with stainless steel equivalents.

Heck, just get out your Dremel and give the stock bolt the shining of its life. Dremel has LOTS of stuff to polish with. That way you don't have to worry about strength, sheer factors, stretching, torque, flux capacitors, photon torpedos or any of that other technical stuff!

 

[yamaha1300rider]

Another good idea Bikerschim

I do indeed have a Dremel but haven't used it for polishing - be interesting to see what can be done to a weathered mill finish capscrew

 

[odot]

Putting caps in is going to be a lot cheaper then using a dremel on each bolt on your scoot. Just don't buy from a harley dealer...they'll take you to the cleaners....

 

[yamaha1300rider]

odot

So far this is the only source I've found in the uk:

Covers

 

[odot]

Oh, uk, eh? First off, sorry dude.....I'd rather live in finland then the u.k......they probably speak better english in finland. Check out www.denniskirk.com....they might be able to ship you something.

 

[jestal]

The unthreaded tip of the bolt is designed for piloting and starting the bolt without crossthreading. It is commonly called a bullet tip or dog point. It is very common to see bolts like that in production where every attempt is made to error proof the assembly process. It is an especially important feature for a spot like that particular bolt is in....... that is locating and piloting several parts so the bolt is used to pull everything together before the threads are started. If you can start the bolt with no problem then the tip has no other functional purpose.

Personally, for that specific location, I would agree with the others that sticking with the OEM bolt is probably a good idea. Not likely that a stainless steel generic fastener is going to be as strong as the forged OEM bolt. That bolt that mounts the side stand is subjected to a lot of load, both in tension and bending so I would be cautious with a replacement. Caliper bolts are loaded purely in shear (other than the tensioning loads) so they are actually subjected to less loads in that respect than the side stand bolt.

Off hand I don't remember if that is a thru hole or not. If it is a thru hole then going to a slightly longer bolt will probably be OK but check for clearance on the other side. IF it is a blind hole then it is best to stay with the OEM length exactly least the bolt bottom and crack the casting or just not tension the joint.

 

[pawtracks]

I think I would look at buying two new ones (if the dremel did not give me good results)

Yamaha part # 90109-10031-00

You can find it on the "stand footrest" page of the parts catalog, part # 31

Probably around $10 for two brand new bolts from Gary McCoy with shipping.

Gary McCoy University Motors 866-551-6478

edit: maybe a little more to the UK, didn't see your location. But I still vote for new OEM.

 

[yamaha1300rider]

Thanks again to odot, jestal and pawtracks

My comments are:

odot - having checked out the prices I'll give the covers a wide berth - I hate to think what a Harley dealer would charge

(yes finns probably speak better english than us brits)

jestal - appreciate the technical aspects, as always. Interesting you refer to forged oem bolts - I noticed that the bolt under discussion and others on the bike have a common green appearance - could be paint but perhaps the forging effect - no doubt you or someone will confirm. Strange no rust found on the shafts/threads :huh:

pawtracks - seems to easiest way to proceed

Cheers

 

[jestal]

I suspect the color is a plating or coating to prevent corrosion. Zincdichromate is common as well as cadmium plating on "foreign" bolts.

By forged I mean the bolt was likely cold headed to form the basic head and bolt shaft and then the threads were rolled into the bolt. The rolling operation upsets material and moves it around, in effect forging it, and creates much stronger threads than cutting the threads. Since rolling the thread extrudes some material higher than the original diameter of the bolt shaft and rolled thread is always formed on a slightly smaller diameter shaft than the final thread diameter. Look at the bolt carefully and you can see the shank is reduced in diameter just where the threads are formed...that is a giveaway for a rolled thread. Very strong bolt. I would leave it in there.